Resistance-type flexible pressure sensor device and preparation method thereof

Abstract

The invention discloses a resistive flexible pressure sensor device and a preparation method thereof, and the method comprises the steps: preparing conductive pressure-sensitive silicone rubber, the size of the conductive pressure-sensitive silicone rubber being at least capable of accommodating the pressing area of two fingers; the surface of the flexible polyimide is plated with copper, two copper electrodes are prepared, conductive adhesive is arranged at one end of each copper electrode, the other end of each copper electrode is connected with a processor, and the processor is used for calculating the pulse beat number according to the collected voltage value; one end, provided with the conductive adhesive, of the copper electrode is adhered to the surface of the conductive pressure-sensitive silicone rubber and is packaged by the flexible polyimide substrate, and at the moment, the conductive pressure-sensitive silicone rubber, the copper electrode and the flexible polyimide substrate are arranged in sequence. The device can accurately detect weak pressure change, and is simple in structure and convenient to manufacture.

Description

Technical Field

[0001] The present invention relates to the field of flexible electronics and pressure sensing, and in particular to a resistive flexible pressure sensor device and a preparation method thereof. Background Art

[0003] In recent years, the field of flexible electronics has developed rapidly, providing technical support for the manufacture of flexible sensors. In the field of health monitoring, flexible sensors have better wearing comfort and play a positive role in daily monitoring of human health status.

[0004] In order to connect with communication equipment, realize real-time information exchange, better fit with skin, more comfortable, and provide more possibilities for personalized health management and physical condition monitoring of more special groups, it is necessary to develop a flexible pressure sensor for human pulse measurement. Existing pressure sensors are hard and not accurate enough for measuring weak pressure changes such as pulse. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a resistive flexible pressure sensor device and a preparation method thereof.

[0006] The specific technical solutions are as follows:

[0007] A method for preparing a resistive flexible pressure sensor device comprises the following steps:

[0008] S1: preparing a conductive pressure-sensitive silicone rubber, the size of which can at least accommodate the pressing area of ​​two fingers;

[0009] S2: Copper is plated on the surface of flexible polyimide to prepare two copper electrodes, one end of the copper electrode is provided with conductive glue, and the other end is connected to a processor, and the processor is used to obtain the number of pulse beats according to the collected voltage value;

[0010] S3: One end of the copper electrode provided with conductive glue is glued to the surface of the conductive pressure-sensitive silicone rubber and encapsulated with a flexible polyimide substrate. At this time, the conductive pressure-sensitive silicone rubber, the copper electrode and the flexible polyimide substrate are arranged in sequence.

[0011] Furthermore, in S2, the copper plating method of the flexible polyimide surface is electroplating.

[0012] Furthermore, one end of the copper electrode glued to the surface of the conductive pressure-sensitive silicone rubber is round.

[0013] A resistive flexible pressure sensor device is prepared according to the method for preparing the resistive flexible pressure sensor device, comprising: a flexible polyimide substrate, a conductive pressure-sensitive silicone rubber, and a copper electrode;

[0014] The flexible polyimide substrate is in the shape of a flat plate;

[0015] There are two copper electrodes, both made of flexible polyimide plated with copper, one end of the copper electrode is bonded to the surface of conductive pressure-sensitive silicone rubber by conductive glue, and the other end is connected to the processor, and the processor is used to obtain the number of pulse beats according to the collected voltage value;

[0016] The size of the conductive pressure-sensitive silicone rubber can at least accommodate the pressing area of ​​two fingers; the side of the conductive pressure-sensitive silicone rubber bonded with the copper electrode is encapsulated by a flexible polyimide substrate.

[0017] Furthermore, the conductive pressure-sensitive silicone rubber has a thickness of 0.5 cm and a cross-sectional size of 3 cm×2 cm or 2 cm×2 cm.

[0018] Furthermore, one end of the copper electrode glued to the surface of the conductive pressure-sensitive silicone rubber is circular, and the radius of the circle is 5 mm.

[0019] Furthermore, the thickness of the flexible polyimide substrate is 25 μm.

[0020] The beneficial effects of the present invention are:

[0021] (1) The device of the present invention has good flexibility and can better fit the human body. In addition, the pressure sensor device is based on the pressure-sensitive properties of conductive silicone rubber, can detect slight pressure changes, detect the human pulse more accurately, and exhibit good pressure sensing properties.

[0022] (2) The device of the present invention has a simple structure, a convenient manufacturing process, reduces manufacturing costs, and is suitable for mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a top view of the resistive flexible pressure sensor device in an embodiment of the present invention.

[0024] Figure 2 is a side view of a resistive flexible pressure sensor device in an embodiment of the present invention.

[0025] Figure 3 4 is a flow chart of a method for preparing a resistive flexible pressure sensor device in an embodiment of the present invention.

[0026] Figure 4 Schematic diagram of a pulse voltage curve of a resistive flexible pressure sensor device in an embodiment of the present invention.

[0027] In the figure, there are a flexible polyimide substrate 1, a conductive voltage-sensitive silicone rubber 2, and a copper electrode 3. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below according to the accompanying drawings and preferred embodiments, and the purpose and effect of the present invention will become more clear. The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] like Figure 1 and Figure 2 As shown, a resistive flexible pressure sensor device includes: a flexible polyimide substrate 1, a conductive pressure-sensitive silicone rubber 2, and a copper electrode 3. The flexible polyimide substrate 1 is in the shape of a plate, and its size is set according to actual needs. There are two copper electrodes 3, both of which are made of flexible polyimide plated with copper (electroplated copper is used in this embodiment), and their shape and size are set according to actual needs. One end of the copper electrode 3 is bonded to the conductive pressure-sensitive silicone rubber 2 through conductive glue, and the other end is connected to the processor, and the processor is used to directly calculate the number of human pulse beats in one minute based on the collected voltage value; the size of the conductive pressure-sensitive silicone rubber 2 can at least accommodate the pressing area of ​​two fingers; the side of the conductive pressure-sensitive silicone rubber 2 bonded with the copper electrode 3 is encapsulated by the flexible polyimide substrate 1 to form a resistive flexible pressure sensor device.

[0030] In order to prepare the above-mentioned resistive flexible pressure sensor device, the embodiment of the present invention also provides a method for preparing the resistive flexible pressure sensor device, such as Figure 3 As shown, the method specifically comprises the following steps:

[0031] S1. Prepare conductive pressure-sensitive silicone rubber: Cut the conductive pressure-sensitive silicone rubber 2 in the way of Chinese medicine pulse diagnosis to ensure that it can accommodate at least two fingers pressing on it at the same time. In this embodiment, the thickness of the conductive pressure-sensitive silicone rubber 2 is 0.5mm, and the cross-sectional dimensions are 3cm×2cm rectangular and 2cm×2cm square; the larger the area of ​​the conductive pressure-sensitive silicone rubber 2, the better the force effect, but the greater its own resistance, and the resistance change caused by pressure is not obvious, so two sizes are designed for comparison, and finally a size with higher measurement accuracy is selected.

[0032] S2. Preparation of copper electrodes 3: Cut the copper-plated flexible polyimide into two copper electrodes 3. In this embodiment, one end of the cut copper electrode 3 is circular, the middle is long strip, and the other end is square. The radius of the circular part is 5mm, the size of the long strip is 0.3cm×2cm, and the size of the square is 5mm×5mm. One end of the copper electrode 3 (the circular end in this embodiment) is adhered with conductive glue, and the other end (the square end in this embodiment) is provided with a soldering point. A wire connected to the lower computer is soldered by tin soldering. The lower computer transmits the collected data to the upper computer (i.e., the processor), and directly calculates the number of pulse beats of the human body in one minute based on the collected voltage value.

[0033] S3, packaging: two copper electrodes 3 are attached to the surface of the conductive pressure-sensitive silicone rubber 2 through conductive glue, and are packaged with a flexible polyimide substrate 1, and the conductive pressure-sensitive silicone rubber 2 is arranged at any position of the flexible polyimide substrate 1; at this time, the structure of the resistive flexible pressure sensor device from top to bottom is the conductive pressure-sensitive silicone rubber 2, copper electrodes 3, and flexible polyimide substrate 1. In this embodiment, the thickness of the flexible polyimide substrate 1 is 25 μm.

[0034] In practical applications, the prepared resistive flexible pressure sensor device can be used for human pulse measurement and plays an important role in daily monitoring of human health.

[0035] The working principle of the resistive flexible pressure sensor device is as follows: In the actual application process of this embodiment, the pulse is the blood flow caused by the beating of the heart, and this flow generates pressure on the arterial wall. When the pulse acts on the resistive flexible pressure sensor device, the conductive pressure-sensitive silicone rubber 2 will deform, resulting in a change in resistance value. Therefore, the pulse pressure can be converted into a change in resistance value. This change in resistance value can be connected to an appropriate circuit through the copper electrode 3, and then converted into a voltage value that can be measured and analyzed.

[0036] Working process: stick one side of the conductive pressure-sensitive silicone rubber 2 in the resistive flexible pressure sensor device to the radial artery of the human wrist, and press it gently with your fingers. The copper electrode 3 is connected to the lower computer through a wire for data collection and processing, and the collected resistive flexible pressure sensor voltage value is sent to the upper computer, and the number of troughs of the voltage curve is calculated in the upper computer, so as to calculate the pulse number in one minute and display it on the user interface.

[0037] Based on the above principle, the resistive flexible pressure sensor device prepared by the present invention is used to measure human pulse. The comparison between five measurement results and actual results is shown in Table 1 below. The pulse voltage curve obtained during a certain human pulse measurement is shown in Table 1. Figure 4 As shown in the figure, a wave similar to "W" formed by two troughs is a pulse beat, and the pulse beat number can be obtained according to the number of troughs of the curve. As can be seen from Table 1, the error of modern digital sphygmomanometers when measuring pulse is usually maintained within ±5bpm, and the difference between the measurement result of the resistive flexible pressure sensor device prepared by the present invention in human pulse measurement and the actual pulse number is within this range, proving that the resistive flexible pressure sensor device can measure pulse more accurately.

[0038] Table 1 Comparison of the measured results and actual results of the resistive flexible pressure sensor device

[0039]

[0040] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A method for preparing a resistive flexible pressure sensor device, characterized in that: The following steps are involved: S1: preparing a conductive pressure-sensitive silicone rubber, wherein the size of the conductive pressure-sensitive silicone rubber can at least accommodate the pressing area of ​​two fingers; S2: Copper is plated on the surface of flexible polyimide to prepare two copper electrodes, one end of the copper electrode is provided with conductive glue, and the other end is connected to a processor, and the processor is used to obtain the number of pulse beats according to the collected voltage value; S3: One end of the copper electrode provided with conductive glue is glued to the surface of the conductive pressure-sensitive silicone rubber and encapsulated with a flexible polyimide substrate. At this time, the conductive pressure-sensitive silicone rubber, the copper electrode and the flexible polyimide substrate are arranged in sequence.

2. The method for preparing a resistive flexible pressure sensor device according to claim 1, characterized in that: In S2, the copper plating method of the flexible polyimide surface is electroplating.

3. The method for preparing a resistive flexible pressure sensor device according to claim 1, characterized in that: One end of the copper electrode glued to the surface of the conductive pressure-sensitive silicone rubber is round.

4. A resistive flexible pressure sensor device, prepared by the method for preparing a resistive flexible pressure sensor device according to claim 1, characterized in that: include: Flexible polyimide substrate, conductive voltage-sensitive silicone rubber, copper electrodes; The flexible polyimide substrate is in the shape of a flat plate; There are two copper electrodes, both made of flexible polyimide plated with copper, one end of the copper electrode is bonded to the surface of conductive pressure-sensitive silicone rubber by conductive glue, and the other end is connected to the processor, and the processor is used to obtain the number of pulse beats according to the collected voltage value; The size of the conductive pressure-sensitive silicone rubber can at least accommodate the pressing area of ​​two fingers; the side of the conductive pressure-sensitive silicone rubber bonded with the copper electrode is encapsulated by a flexible polyimide substrate.

5. The resistive flexible pressure sensor device according to claim 4, characterized in that: The conductive pressure-sensitive silicone rubber has a thickness of 0.5 cm and a cross-sectional size of 3 cm×2 cm or 2 cm×2 cm.

6. The resistive flexible pressure sensor device according to claim 4, characterized in that: One end of the copper electrode glued to the surface of the conductive pressure-sensitive silicone rubber is circular, and the radius of the circle is 5 mm.

7. The resistive flexible pressure sensor device according to claim 4, characterized in that: The thickness of the flexible polyimide substrate is 25 μm.

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